DESCRIPTION (appended verbatim from investigator's abstract): The long range objectives of this research are to further our understanding of the dynamical behavior of aggregates of interacting cells, and to apply this knowledge to problems of cell movement and pattern formation in developmental biology and to problems in physiology. The major projects are: (1) studies on pattern formation in development, (2) studies on bacterial signal transduction, chemotaxis and pattern formation, and (3) studies on calcium dynamics in glial cells. The aims under (1) are to study pattern formation in models of a growing limb and to analyze new models for pattern formation and cell movement in Dictyostelium discoideum. The aims under (2) are to develop and analyze a model for control of the flagellar motor in E. coli, to use this in simulation of bacterial motion, to analyze stochastic models of motion at the population level, and to study pattern formation in growing colonies. The objectives under (3) are to develop models of calcium dynamics in glial cells and to study the role of spatial heterogeneity of channels and stochastic channel openings in the initiation of calcium waves, and the role of intercellular communication via direct and indirect pathways in determining the type of wave and its amplitude, width, and range of propagation. The research in (1) will advance our understanding of basic processes in developmental biology such as signal transduction, cell and tissue motion, and pattern formation. A better understanding of these fundamental processes will contribute to a better understanding of how systems respond to their environment, how normal development can be disrupted and perhaps abnormal development corrected, and how certain components of the immune system function. The results of the work in (2) will contribute to our understanding of how extracellular signals are transduced into motor control in bacteria, how the microscopic behavior of individuals is reflected in population level descriptions, and how nutrient supply and chemotactic factors control pattern formation. The work in (3) will lead to a better understanding of calcium dynamics in glial cells, and will thereby advance our understanding of neural development, epilepsy and neuro degenerative diseases.